Field of the Disclosure
This disclosure relates an organic light emitting diode display device, and more particularly to an organic light emitting diode display device and a manufacturing method thereof which are adapted to enhance reliability.
Description of the Related Art
Various kinds of flat panel display devices that can replace heavy and bulky cathode ray tubes (CRTs) have been recently developed. Examples of the flat panel display devices include a liquid crystal display (LCD) device, a field emission display (FED) device, a plasma display panel (PDP), and a light-emitting diode display device.
The light-emitting diode display device is classified into an inorganic light-emitting diode display device and an organic light-emitting diode (OLED) display device according to the material of a light emission layer. Such a light-emitting diode display device has good characteristics, including a rapid response time, a high light-emitting efficiency, a high brightness, and a wide viewing angle because of being self-luminous.
The OLED includes an organic light-emitting compound layer configured to emit light, and an anode electrode and a cathode electrode facing each other with the organic light-emitting compound layer therebetween. The organic light-emitting compound layer includes a hole injection layer HIL, a hole transport layer HTL, an emission layer EML, an electron transport layer ETL and an electron injection layer EIL.
Such an OLED injects holes and electrons to the emission layer EML each through the cathode and anode electrodes and enables the emission layer to emit light by energy from excitons which are generated in an excitation process that the holes and the electrons are recombined with each other in the emission layer EML. In accordance therewith, the OLED display device electrically controls the quantity of light generated in the emission layer EML of the OLED and displays an image.
The OLED display device includes a thin film transistor (TFT), a planarization film formed in such a manner as to cover the TFT, an anode electrode connected to the TFT, a bank pattern formed on the TFT and the anode electrode, an organic light-emitting compound layer formed on the bank pattern and the anode electrode, and a cathode electrode formed on the organic light-emitting compound layer.
The OLED display device includes a buffer layer, a semiconductor active pattern, a gate insulation film, a gate metal pattern, an interlayer insulation film, a source/drain metal pattern and a passivation film which are sequentially formed on a substrate. The gate metal pattern includes a gate electrode of the TFT. The source/drain metal pattern includes source and drain electrodes of the TFT. The anode electrode is connected to the drain electrode of the TFT through a contact hole which penetrates through the passivation film.
Such an OLED display device can be defined into a display area used to display images and a non-display area surrounding edges of the display area. In the non-display area, a circuit portion and a ground connection portion can be formed. The circuit portion is used to apply drive voltages to a plurality of drive lines formed in the display area.
Similarly to the display area, another TFT, the planarization film, the anode electrode and so on are formed in the circuit portion of the non-display area.
However, residual materials within the planarization film formed in the circuit portion of the non-display area can be out-gassed with the lapse of time. The out-gassed residual materials affect the organic light-emitting compound layer formed in the display area. Due to this, the organic light-emitting compound layer can deteriorate.
The deterioration of the organic light-emitting compound layer causes faults and forces the reliability of the OLED display device to deteriorate.